Compensating device



April 1943- E. JEKUEBERT ET AL 2,316,004

GOMPENSATING DEVICE Filed July 17, 1941 s Sheets-Sheet 1 INVENTORSV Edward J Kueerf BYHallzlal-d 1. Penfol'd ATTORNEY April 1943- E. J. KUEBERT ET AL 2,316,004

COMPENSATING DEVICE Filed July 17, 1941 3 Sheets-Sheet 2 INVENTORS-I Edwm'd .I Kaeberi' BYHiZZz'ardEPenfqlal pr l 6, 1943. EQJ. KUEBEVRT ETA'L 2,316,004

COMPEiISATING DEVICE Filed July 17, 1941 3' Sheets-Sheet 3 I iir Q Patented Apr. 6, 1943 COMPENSATING DEVICE Edward J. Kuebert, Bellmore, and Hilliard F. Penfold, Hollis, N. Y., assignors to Fairchild Aviation Corporation, Jamaica, N. Y., acorporation of Delaware Application July 17, 1941, Serial No. 402,798

7 Claims. (01. 250-11) This invention relates to a compensating device for augmenting or decreasing an input value by any predetermined variable or fixed amount, and transmitting the corrected value to an output. More particularly and illustratively, the invention is directed to a compensating device which automatically compensates for the deflection of a radio wave from its true bearing, and

delivers an output, the value of which is proportional to the value of the true bearing of the wave.

Radio compasses have come into common use as part of the navigating equipment on aircraft. Such compasses are for the most part equipped with revoluble loop antennae to intercept a radio wave or signal regardless of the location of its transmitter. The difficulty, however, lies in the fact that the angle between the wave and the line of flight of the airplane is often such that the wave is intercepted and deflected by various parts of the airplane, such as the engines, wings, etc., so that when the wave is picked up by the radio compass the true bear ing of the wave is not indicated on the radio compass card. For example, if the airplane is flying due north, and the true bearing of the wave is 45 west of north, the wave might be intercepted and deflected by one of the airplane engines to such an extent as to indicate an apparent bearing of 30 west of north.

Inasmuch as the wave deflecting characteristics of an airplane can be readily determined and plotted as a definite value, it but remains to add or subtract such value as the case may be to the apparent value of the bearing of the wave to obtain a corrected value identical with that of the true bearing of the wave. In other words, using the example given above, the position of the radio compass loop would indicate an apparent value of 30, but it having been predetermined that the deviation for that setting of theloop is plus 15, the value of the true bearing is the sum of the apparent value and the airplane characteristic deviation value, or 45.

Accordingly, it is among the objects of this invention to provide a simple, compact, inexpensive and sturdy compensating device which is capable of increasing or decreasing an apparent value by an amount equal to the difference between the apparent value and the true value. 7

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts as will be exemplified in the structure to be hereinafter described, and

iii)

the scope of the application oi which will be indicated in the following claims.

In the drawings, wherein there is shown one of the Various possible embodiments of our invention,

Figure 1 is a schematic view of our compensator connected to a radio compass and to an indicating mechanism;

Figure 2 is an enlarged top plan view of the compensating device;

Figure 3 is an enlarged bottom plan View of the compensating device;

Figure 4 is a sectional elevation taken along the line 4--& of Figure 3; and,

Figure 5 is an enlarged fragmentary perspece tive view of the compensating device, portions thereof being broken away for illustrative clarity.

Similar reference characters refer to similar parts throughout the several views of the drawings.

Referring first to Figure l, a radio compass, generally indicated at H], includes a rotatable shaft II which supports a loop antenna l2. Shaft I! also supports a gear l3 which rotates with loop 12 and meshes with a gear Hi rotatably mounted on a bracket l5 secured to and extending from compass It. Gear It carries a radially spaced driving pin 16 which transmits an input value to our compensator generally indicated at IT. Compensator I! has an output shaft I 8 which extends through gear M and bracket Iii, being freely rotatable with respect thereto, and provides a drive for the self-synchronous motor of the transmitter IQ of atelemetering device. Transmitter I9 is connected by an electrical cable 20 to the receiver or indicator 2| of the telemetering device, which indicates the value ofthe output of compensator I! (Figure 2) includes a base or mounting plate 22 suitably drilled in the corners, as at 23, to provide holes through which securing studs may extend. Secured to the top base 22 is a ring 24 graduated in degrees on both sides, and accordingly comprising a reversible loop bearing scale adapted for clockwise or counterclockwise rotation for indicating the uncorrected angular position of the radio compass loop antenna l2 (Figure 1). Ring 24 is bolted to base 22 by bolts 25 which extend through ears 26 extending from the ring. Preferably ears 26 are slotted so as to facilitate assembly of the ring to the base.

A loop bearing pointer generally indicated at 2'! isrevolubly mounted on base 22 above scale 26 in a manner to be described, and includes a short arm 23 and a long arm 29 lying on opposite sides of its pivotal axis. The short arm 28 of this pointer includes a reference mark 3 which registers on the graduations of scale 24 to indicate the setting of compass loop l2, movement of the loop being directly reflected by movement of pointer 21, as will be described below. Hence reference mark 36 on pointer 21 indicates the angular setting of loop i2 (Figure 1) and accordingly indicates the value of the apparent bearing of the radio wave intercepted by the loop antenna.

The long arm 29 of loop pointer 21 is graduated in degrees on opposite sides of a zero ref ence point, thus providing a positive correction scale 3| and a negative correction scale 32. Over the correction scales 3| and 32 moves the end 33 of a correction pointer 34 mounted on base 22 and revoluble about the pivotal axis of loop pointer 21. Movement of correction pointer 34 over correction scales '31 and 32 indicates onthe correction scales for any given setting of loop reference indicator 36 a value which represents the difference between the value of the apparent bearing of the radio wave and the value of the true bearing thereof. Hence from loop scale 24 and correction scales 3| and L32 the true bearing of the radio wave can be readily calculated by adding or subtracting, as the case may be, the indicated deviation n the correction scales to or from the value of the apparent hearing as indicated by 100p reference .30.

The deviation of loop antenna i2 which is reflected by the movement of loop pointer 21, will hereinafter be considered and termed the input to compensator l1, and what will hereinafter be termed and considered as the output of the compensator will be the deviation of loop bearing pointer 21 as modified by correction pointer 34, all as effected by mechanisms now to be described.

Base 22 (Figure 4) includes an outer annular downwardly projecting shoulder 35 and an inner annular downwardly projecting shoulder 36 which together form a circular channel 3'! within which is disposed mechanism to be described hereinbelow. Annular shoulder 35 forms in base 22 a centrally disposed opening within which is pressed a ball bearing 38 which journals 2. bushing 39 pressed about the reduced shank ii) of a sleeve generallyindicated at 41. On the upper end of sleeve shank All is disposed a collar 42 through which a pin 43 extends into a keyway 44 formed in sleeve shank 40 so that rotation of the sleeve is imparted to the collar. The upper end of collar 42 has a shoulder 45 formed thereon on which loop bearing pointer 21 is secured as by swaging over the end of the collar. Thus any rotational movement imparted to sleeve 41 rotates pointer '21 about the axis of the sleeve.

Extending radially from the enlarged lower portion 46 of sleeve M is a tapering arm 61 (see also Figure 3) having a notch it formed therein. It is into this notch :38 that pin H (Figure 1.) extends, and accordingly it will appear that the rotation imparted to gear l4 through movement of loop 52 is transmitted by pin it to arm 4'! (Figure 4) and accordingly through sleeve M and collar '42 to loop bearing pointer 21. Thus pointer 21 indicates the deviation of the radio compass loop antenna, i. e. the input referred to above.

As shown in Figures 4 and 5, sleeve 4! is mounted on a hollow shaft generally indicated at 49, through which extends output shaft [8 (Figure 4). Sleeve 4% is movable relative to shafts 4!! and I8, and shaft I8 is movable relative to shaft t?! for purposes of adjustment of indicator 2|, as will be pointed out hereinbelow. The lower end of hollow shaft 49 (Figure 4) has secured thereto a hub 52 from which extends a radial arm 52 (Figure 5). An arm generally indicated at 53 has one end 53a thereof pivotally connected to the outer end of arm 52, while its free end 531) rotatably mounts a roller 54. Arms ll and 53 are connected together by a link 55, the opposite ends of which are respectively pivotally connected to the two arms so that movement of arm 41 by pin It, as described above, results in movement of arm 53 and accordingly arm 52 and hollow shaft #39. In other words, the input to arm t? is transmitted by way of link 55, arm 53 and arm 52 to hollow shaft 49.

The upper end of shaft 59 has a reduced portion 4% threaded to receive a nut 56 which, when taken up, clamps correction pointer 35 tightly in place on the shaft so that the pointer moves therewith. The upper end 4% of shaft 39 is further reduced and threaded and has its sides split as shown at ite (Figure 5). When a tapered nut 51 is threaded on end @921 of the shaft, this end is squeezed against the upper end of shaft E8 to connect shafts it) and is together. Accordingly, rotation of shaft 59 is imparted to output shaft is.

It may now be seen that the input to compensator H is transmitted to an output as follows: loop 52 (Figure 1) gears 53 and it, input pin i6 (Figure 5), arm 27, link 55, arm 53, arm 52, hollow shaft 49 and output shaft it. It will also appear that as long as arms 53 and ll bear a fixed relationship to one another, the output value of shaft 153 is identical to the input value to the compensator, i. e. sleeve 4i (Figure i) and shaft l8 rotate together through the same number of degrees.

As pointed out hereinbefore, however, it becomes necessary under certain circumstances to augment or decrease the input value by predetermined variable or fixed amounts so that the output value will be a compensated value and accordingly an accurate indication of the condition being interpreted. To this end, roller 54 (Figures 3 and 4) rides along an adjustable cam generally indicated at 58, the contour of which may be varied in accordance with predetermined characteristics of thestructure on which the radio compass is mounted, in the present instance an airplane.

Cam 5B is formed by a tightly coiled circular spring which is retained in grooves 59 (Figure 4) formed in shoes 60 (Figure 3) adjustably disposed within annular channel 31, in a manner to be described.

Each of shoes (iiihas a threaded hole 6| extending therethrough which threadably receives a screw 62, the outer end 62a of which is loosely received in a hole 63 drilled in shoulder 35,

and the inner end 622) of which is loosely disposed in a hole 6Q formed in inner shoulder 33. The outer end 620. of screw 62 has a hexagonal hole 65 formed therein for the reception of a key or the like (not shown) by which the screw can be turned. Hence, as screw 62 is turned one way, shoe 6!! is moved radially outwardly, for example, whereas if the screw is turned the other way, shoe is moved inwardly toward the axis of shaft 18, for example. Thus, as is more clearly shown in Figure 3, each of shoes 8%! is radially adjustable and accordingly, with their grooves 59, form a channel of variable peripheral contour within which cam 58 is disposed. Screws G2 and also shoes 60 are held in their adjusted positions by the tension of cam spring 58, and it is preferred that the tension of the spring be of sumcient value to hold the shoes against inadvertent displacement from their adjusted positions. It will now appear that cam 58 may be contoured substantially as desired within the limits of annular channel 31, through the radial adjustment of shoes 60.

As shown in Figure 5, a spring 65 is coiled about lower portion 46 of sleeve 4| and has one end 65a connected to a stud 66 extending from arm 41, the other end 6511 of spring 65 being connected to the pivot pin 61, which pivotally connects arms 52 and 53. Thus, spring 65 (Figure 3) imparts a clockwise bias to arm 41 and a counterclockwise bias to arm 52, which latter.

bias forces arm 53 to the right, as viewed in Figure 3, and accordingly always pulls roller example, when roller 54 rides over a high spot on cam 58 as, for example, portion 58a thereof, the radial distance between the roller and shaft l8 increases, with the result that arm 52 is moved outwardly, and accordingly hollow shaft 49 is moved clockwise. shaft 49 is imparted to correction pointer 34 (Figure 4) which accordingly moves counterclockwise, as viewed in Figure 2. This counterclockwise movement of hollow shaft 49 (Figure 4) is also relative to sleeve 4|, it being noted that movement of the sleeve causes movement of loop bearing pointer 21, with the result that correction pointer 34 (Figure 2) moves relative to loop bearing pointer 21. This relative move ment between pointers 34 and 21 is indicated on one or the other of scales 3|, 32, and accordingly a plus or minus correction of the loop bearing deflection as indicated by reference 30is given. Furthermore, the compensating movement of hollow shaft 49 (Figure 4) is also imparted to output shaft is through the lock nut mechanism described, so that the output of this shaft is augmented or decreased by a predetermine amount for a given setting.

Similarly, when roller 54 (Figure 3) rides over a low spot on cam 58, such as portion 58b thereof, roller 54 moves toward shaft l8, resulting in counterclockwise movement of arm 52 and shaft 49, and accordingly clockwise movement of correction pointer 34, as viewed in Figure 2. relative to loop bearing pointer 21.

As noted above, shoes 60 are individually adjustable toward and away from the axis of shaft I 3 which is preferably vertical when compensator I! is installed on the airplane. Also edge 22a (Figure 2) of compensator base 22, for present purposes, will be considered as the leading edge of the compensator and lying at right angles to the longitudinal axis of the airplane or its line of flight. When the compensatoris so installed This clockwise movement of till that its longitudinal axis is in perfect alignment being transmitted from a station in front of the airplane. Under such circumstances the angle between the wave bearing and the longitudinal axis of the airplane is zero degrees. Thus, loop bearing pointer 21 (Figure 2) would indicate 0 when the plane of the loop antenna l2 (Figure 1) is at right angles to the longitudinal axis of the airplane. If the correction pointer 34 indicates plus or minus for this position, the shoe or shoes 60 (Figure 3) adjacent roller 54 are adjusted to move the adjacent portion of cam 58 and accordingly the roller until the correction pointer indicates zero. After shoe or shoes 60 have been so adjusted, output shaft I8 is adjusted to obtain a zero reading on the receiver indicator 2| (Figure 1), To this end lock nut 51 (Figure 4) is loosed to relax the grip of the split end 4% of hollow shaft 49 on the upper end of output shaft l8 to permit turning the output shaft relative to the hollow shaft. The output shaft is then turned in one direction or the other until indicator 2| (Figure 1) registers the same as loop bearing pointer 21 (Figure 2), in this instance, zero. Thus, the indicated bearing of indicator 2| and that of the radio path are consistent.

Next the airplane is pivoted clockwise, for example 15, the desired angular displacement between adjacent shoes 60 (Figure 3) although any other suitable spacing can be used. In this position it is known that the angle between the radio path and the longitudinal axis of the airplane is 15. The loop antenna is then adjusted until it is on the path of the wave and such adjustment is reflected by movement of loop bearing pointer 21 (Figure 2) to or towards the 15 mark on scale 24. If no portion of the airplane is intercepting the radio wave at this position, and accordingly is not deflecting it, loop I2 (Figure 1) will have moved 15 and this bearing will Joe in dicated by pointer 21 on scale 24. Assuming no radio wave deflection, the position of correction pointer 34 can be set to zero by proper adjustment of the shoe or shoes 60 (Figure 3) adjacent roller 54 for this setting. By this adjustment of the correction pointer output shaft l 8 is moved, this movement being transmitted to indicator 2! to correct its reading.

Assuming, however, that pivoting the airplane 15 from the 0 position brings into position some portion of the airplane structure which intercepts and accordingly deflects the radio wave, then angular adjustment of loop l2 (Figure 1) until it is on the path will be through an angle which is r greater or less than 15 by an amount propor tional to the radio wave deflection. Under such circumstances the loop bearing pointer 21 (Fig ure 2) will indicate an apparent bearing greater or less than 15 and it becomes necessary to set in the proper correction. This is accomplished by first determining the difference between the apparent and true bearing (assume the apparent bearing is 20", 5 more than the true bearing). The shoe or shoes 50 (Figure 3) adjacent roller 54 are then adjusted so as to move correction pointer 34 to the 5 mark on its minus scale 32 so that the difference between the apparent bearing on scale 24 and the correction on scale 32 is 15. This adjustment of the correction pointer is transmitted to output shaft i8, as described above, so that the total deflection of the output shaft is 15, i. e. the true bearing of the radio path which is also recorded on indicator 2!.

It will accordingly appear that the airplane can be pivoted 360 in 15 increments, and for each increment the proper correction set into compensator ii through the adjustment of cam 58. Hence, regardless of the line of flight of the airplane when aloft, the true bearing of a radio wave can be immediately determined regardless of the deflection of its path by the airplane structure.

After compensator H has been adjusted, as described above, it operates as follows: The airplane navigator revolves loop 12 until it is on the desired radio wave path. This movement of the loop is imparted through gears l3 and 14 (Figure l) and through pin l6 (Figure to arm 41, causing the arm to rotate in one direction or another. This movement of arm 4'! rotates sleeve 4| causing movement of direction pointer 21 to a position wherein its reference mark 30 (Figure 2) indicates on scale 24 anapparent bearing of the radio path. However, as arm 4'! (Figure 5) is moved, its movement is also imparted to arm 53 by reason of connecting link 55, and accordingly cam-follower 54 is moved over cam 58 to the set position. Assuming that this position coincides with a high spot on cam 53, arm 53, and accordingly arm 52, are pivoted clockwise, as viewed in Figure 5, to move hollow shaft 49 relative to sleeve ll. This movement ofshaft 49 results in movement of correction pointer 34 relative to loop bearing pointer 27 so that the correction pointer registers on the minus scale 32 (Figure 2) the difference between the apparent loop bearing, as indicated by reference mark 3%, and the true bearing of the radio Wave. This corrective movement of hollow shaft 39 (Figure 5) is also imparted to output shaft l8, which transmits the movement to telemeter motor l9 which, in turn, affects indicator 2! so that its pointer indicates the true bearing of the radio wave.

It might be noted that indicator 2| may conveniently be located in the cockpit of the airplane in a position readily visible to the pilot or navigator under cricumstances which would preelude a readily visible disposition of compensator H and the scales thereon.

It will now appear that we have provided a compensating device which practicably and efficiently carries out the several objects hereinabove set forth.

As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth, or shown in the accompanying drawings, is to be interpreted as illustrative and not in a limiting sense. 1

We claim:

1. A compensating device for use with a radio compass having a revoluble loop antenna, in combination, a driving mechanism connected to and operable :by said antenna upon rotation thereof, a scale, a rotatable sleeve, means connecting said sleeve to said driving mechanism for operation thereby, a pointer secured to said sleeve and rotatable thereby over said scale to indicate there on the setting of said loop antenna, a hollow shaft rotatably mounted within said sleeve, means connecting said shaft to said sleeve and accordingly to said driving mechanism for operation thereby, an adjustable device for effecting movement of said shaft relative to said sleeve during the rotational movement of said shaft and sleeve in proportion to a difference between the antenna bearing and the true bearing of the radio wave intercepted thereby, and a pointer connected to operation thereby,

said shaft and located adjacent said first pointer to indicate relative movement between said sleeve and said shaft whereby to visibly determine said difference between the antenna bearing and the true bearing of the radio wave.

2. A compensating device for use with a radio compass having "a revoluble loop antenna, in combination, a driving mechanism connected to and operable by said antenna upon rotation thereof, a scale, a rotatable sleeve, means connecting said sleeve to said driving mechanism for operation thereby, a pointer secured to said sleeve and rotatable thereby over said scale to indicate thereon the setting of said loop antenna, a hollow shaft rotatably mounted within said sleeve, means connecting said shaft to said sleeve and accordingly to said driving mechanism for an adjustable device for effecting movement of said shaft relative to said sleeve during the rotational movement of said shaft and sleeve in proportion to a difference between the antenna bearing and the true bearing of the radio wave intercepted thereby, a pointer connected to said shaft and located adjacent said first pointer to indicate relative movement between said sleeve and said shaft whereby to visibly determine said difference between the antenna bearing and the true bearing of the radio wave, a telemetering device having an indicator adapted to be located remotely from said pointers for indicating the true bearing of the radio wave, and means connecting said telemetering device to said shaft.

3. A compensating device for use with a radio compass having a revoluble loop antenna, in combination, a driving mechanism connected to and operable by said antenna upon rotation thereof, a scale, a rotatable sleeve, means connecting said sleeve to said driving mechanism for operation thereby, a pointer secured to said sleeve and rotatable thereby over said scale to indicate thereon the setting of said loop antenna, a hollow shaft rotatably mounted within said sleeve, means connecting said shaft to said sleeve and accordingly to said driving mechanism for operation thereby, an adjustable device for effecting movement of said shaft relative to said sleeve during the rotational movement of said shaft and sleeve in proportion to a difference between the antenna bearing and the true bearing of the radio wave intercepted thereby, a pointer connected to said shaft and located adjacent said first pointer to indicate relative movement between said sleeve and said shaft whereby to visibly determine said difference between the antenna bearing and the true bearing of the radio wave, a second shaft disposed within said hollow shaft and secured thereto so as to move directly therewith, and means connected to said second shaft and responsive to its movement for indicating the true bearing of said'wave.

4. A compensating device for use with a radio compass having a revoluble loop antenna, in combination, a driving mechanism connected to and operable by said antenna upon rotation thereof, a scale, a rotatable sleeve, means connecting said sleeve to said driving mechanism for operation thereby, a pointer secured to said sleeve and rotatable thereby over said scale to indicate thereon the setting of said loop antenna, a hollow shaft rotatably mounted within said sleeve, means connecting said shaft to said sleeve and accordingly to said driving mechanism for operation thereby, an adjustable device for effecting movement of said shaft relative to said sleeve during the rotational movement of said shaft and sleeve in proportion to a difference between the antenna bearing and the true bearing of the radio wave intercepted thereby, a pointer connected to said shaft and located adjacent said first pointer to indicate relative movement between said sleeve and said shaft whereby to visibly determine said difference between the antenna bearing and the true bearing of the radio wave, a second shaft disposed within said hollow shaft, means adjustably connecting said second shaft to said hollow shaft so that said shafts rotate together, and means connected to said second shaft and responsive to its total movement for indicating a true bearing of said wave.

5. A compensating device having an input shaft and an output shaft, said shafts being relatively movable, a scale, a pointer connected to said input shaft and movable thereby along said scale, said pointer having graduations thereon, a third shaft connected to said output shaft and movable therewith relative to said input shaft, a pointer connected to said third shaft and movable thereby over said graduations to indicate on said first pointer the amount of relative movement between said input and output shafts, and cam means for moving said third shaft relative to said input shaft when it is driven thereby so that the movement of said output shaft equals the movement of said input shaft plus or minus the relative movement between said input shaft and said third shaft.

6. A compensating device having an input shaft and an output shaft, said shafts being relatively movable, a scale, a pointer connected to said input shaft and movable thereby along said scale, said pointer having graduations thereon, a third shaft connected to said output shaft and movable therewith relative to said input shaft, a pointer connected to said third shaft and movable thereby over said graduations to indicate on said first pointer the amount of relative movement between said input and output shafts, cam means for moving said third shaft relative to said input shaft when it is driven thereby so that the movement of said output shaft equals the movement of said input shaft plus or minus the relative movement between said input shaft and said third shaft, and means connected to said output shaft for indicating the total movement thereof whereby to visibly determine the amount of movement of the input shaft, the relative movement of the input and output shafts, and the sum of or the difference between the movements of the input shaft and output shaft.

7. A compensating device for use with a radio compass having a revoluble loop antenna, in combination, a driving mechanism connected to and operable by said antenna upon operation thereof, a scale, a first member adapted to be driven by said driving mechanism, means connecting said first member to said driving mechanism for operation thereby, a pointer secured to said first member and movable thereby over said scale to indicate thereon the setting of said loop antenna, a second member, means connecting said second member to said first member and accordingly to said driving mechanism for operation thereby, an adjustable device for effecting movement of said second member relative to said first member during the movement of said members in proportion to a difference between the antenna bearing and the true bearing of the radio wave intercepted thereby, one surface of said pointer having a scale thereon, and a second pointer connected to said second member and disposed adjacent said first pointer to indicate relative movement between said first member and said second member whereby to visibly determine the difference between the antenna bearing and the true bearing of the radio wave.

EDWARD J. KUEBERT. HILLIARD F. P'E'NFOLD. 

